As I opened the local paper and saw my engagement announced in heavy bold lettering, I realised things had gone too far. There, in a rose-bordered box surrounded by the obituaries of the passably famous, were the words ‘Forever Bound'. I gulped. It wasn't that I was experiencing pre-wedding jitters. In part, I was concerned because I had received the offending item on my birthday in an anonymous brown envelope. The main problem, however, was that as far as I knew I wasn't about to get married. I was pretty sure I didn't even have a girlfriend. The Ham & High had scooped me on the entire relationship.

I called my friend Charlotte, who I suspected was responsible. She was allegedly my fiancée, so that was a clue. She was particularly pleased with herself when she picked up the phone. "Did you get it?" she trilled. "Yes, I can't believe Sheila Allen died," I quipped. "Ha. Very funny. Happy Birthday." Yes, this was a birthday present, of sorts. A few years ago I started a joke with her, and now it was getting a bit out of hand.

Charlotte is like the little sister I never had. We met through our families aged fourteen, young enough for our relationship to depend entirely on mutual irritation, but old enough to be awkwardly flirtatious. It was a bit like an episode of Hey Arnold!, but with both of us playing Helga. This occasionally verged on the inappropriate: in retrospect, the time I ended up in the kitchen wrapped in cling-film probably seemed a little fetishistic to adult company. Eventually we made peace, but I was less successful than her in dropping our acrimonious double-act, so the years proceeded with affectionate insults, diagnoses of psychological delinquency, prophesies of perennial spinsterhood and so on.

This curious dynamic may explain why I decided three years ago to give her a self-help book and an autographed picture of myself for her birthday. It sounds odd, even cruel, but I knew she'd find it funny. When she's truly amused, Charlotte has a tendency to dissolve into silent laughter for extended periods. She looks like she's in the grip of a nervous attack. I always feel particularly satisfied if I can make her do this, and the best way seems to be to insult her whilst simultaneously making myself ridiculous. That day, immobilisation through inaudible cackling was achieved.

But the joke didn't stop: Charlotte adopted the identity of a crazed fan, and started sending me obsessive gifts. Not wanting to be outdone, I responded with more homemade merchandise featuring myself. An escalating cycle emerged. My collection of gifts from her now includes a mug with a photo of my name draped across an S&M-garbed woman's bum-which, I often forget, makes me look pretty misogynistic at breakfast-a pillow with the tagline "I want your babies", and a horrific CGI-rendition of our hypothetical child (it had my stubble). In addition to the photo, Charlotte has a Twelve-Months-of-Theo Calendar and a gold-framed oil painting of me riding Napoleon's horse, shirtless.

At her last birthday party, I sneaked into her room and replaced her bedding with a full me-themed set, including a duvet cover with an A0 self-portrait, and two cheeky-winking-me pillow covers. This, I felt at the time, was a decisive move. Then she announced our engagement, which is problematic, because I may have to go through with it. Partly, it's the publicity. To this day, if I google myself, it still shows up twice on the first page. Former schoolteachers have already congratulated me on facebook. More importantly, though, I don't know how else to top it. I'm a victim of my own warped reality. I'd rather be Forever Bound than back down. The only option seems to be to organise the ceremony, and hope she'll blink at the altar. If she doesn't, well... I'm not sure how I'll tell our kids that they're the result of an extended practical joke. But then, on the bright side, the divorce will be a lot easier on them. Plus, I'm fairly sure I can make her snort at the alimony hearing.

Read more pieces from past issues here.